Return to Play and Clinical Outcomes after All-Inside, Anterior Cruciate Ligament Reconstruction in Skeletally Immature Athletes

Abstract

Objectives: Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are on the rise because of increased participation and level of competition within sports, sports specialization and societal factors. Conservative treatment of these injuries has a poor natural history due to recurrent instability with meniscal and articular cartilage damage. The purpose of this study was to evaluate the results of an all-inside, physeal-sparing ACL reconstruction in skeletally immature athletes, with a focus on return to play. Methods: Forty-two skeletally immature athletes (mean chronologic age 12.7 yrs, [range 10-15]) were prospectively evaluated following an all-inside ACL reconstruction utilizing hamstring autograft. The mean bone age (Greulich and Pyle method) was 13.5 years. There were 10 females and 32 males. Twenty-six patients had an all-epiphyseal (AE) ACL reconstruction and 16 patients had a partial transphyseal (PTP) ACL reconstruction, which spared the femoral physis but crossed the tibial physis. The PTP option was reserved for patients with minimal proximal tibial growth remaining. Fourteen athletes were involved in recreational sport and 28 participated competitively. Lacrosse (36%) and Soccer (32%) were the two most common sports associated with ACL injury in our cohort. All athletes were evaluated with a physical examination, KT-1000 arthrometry, isokinetic testing, validated outcome scores including the International Knee Documentation Committee score (IKDC), the Lysholm score and Marx activity rating scale. Standing radiographs and SPGR MRI analysis was performed at 6, 12 and 24 months post-op depending upon skeletal age. A ‘Return to Play’ performance analysis was also performed where symmetry, alignment control and the ability to decelerate were assessed during progressively challenging movement patterns encountered in sport. Results: At a mean follow-up of 16.7 months (range 12-24), the mean IKDC score was 92.9 ± 7.2, the mean Lysholm score was 97.7 ± 4.6 and the mean Marx activity rating scale score was 12.4 ± 3.5. Lachman and pivot shift testing was negative in all patients. The mean side-to-side difference in the KT-1000 arthrometry was 0.9 ± 0.7 mm, with the maximum difference in the cohort being 2 mm. Isokinetic testing showed a mean deficit of 4.1% in extension torque and 9.2% in flexion torque at a repetition speed of 180 degrees per second. No angular deformities, significant leg length discrepancy or physeal disturbances were observed on postoperative radiographs or MRI. One athlete had a traumatic graft disruption at 12 months and underwent revision ACL reconstruction and one athlete sustained a contralateral ACL rupture at 11 months. The mean time for return to unrestricted competitive activity after successful completion of the ‘Return to Play’ analysis was 12.5 +/- 1.3 months from the time of surgery. Conclusion: An all-inside, physeal-sparing ACL reconstruction technique using hamstring autograft demonstrates excellent subjective and objective clinical outcomes in skeletally immature athletes without growth disturbance. ‘Return to Play’ assessment is an important tool to guide the young athlete and her or his family regarding resumption of competitive sports. In our experience, athletes were on average released for full return to sport after 1 year from ACL reconstruction.